DESCRIPTION: Since the last century many attempts were made to predict the life span of children from that of their parents and to understand the genetic and cultural mechanisms of familial transmission of human longevity. Surprisingly, for this long standing problem there is still no consensus even for the most basic fundamental issues, such as the relative importance of the maternal and paternal influence on offspring survival. Is human longevity inherited more strongly along the maternal line (consistent with cytoplasmic, mitochondrial inheritance) as demonstrated in several studies? Or, on the contrary, is there a predominance of paternal longevity influence on offspring life span as reported in other numerous publications? The purpose of this project is to examine the mechanisms of familial transmission of human longevity using more accurate, extensive and complete genealogical data as well as innovative methods of their secondary analysis (adjustment for secular trends in life expectancy, parental age effects and non-linear effects of parental longevity). The specific aims of this biodemographic study are: (1) To determine the type of the dependence of offspring longevity on parental longevity -- whether it is linear (standard assumption in quantitative genetics), decelerating (expected in the case of early selection out of shorter-lived parents) or accelerating (predicted by the evolutionary theory of aging and by mutation accumulation hypothesis in particular). The investigators' previous preliminary findings, that the familial transmission of human longevity is particularly high in the case of longer-lived parents, will be tested in this study on larger data sets; (2) To examine whether the familial transmission of longevity is more expressed for the children born to younger parents is expected both for genetic reasons (higher genetic diversity of younger parents) and for cultural reasons (higher overlapping between parental and offspring life cycles); (3) To analyze the relative importance of paternal versus maternal longevity influence on son's and daughter's life span in relation to different hypotheses of longevity inheritance (the role of cytoplasmic inheritance in particular) and (4) To increase the sample size of the genealogical longevity database on European royal and noble families and to investigate other data sources for developing a larger (R01) research project on the same issue where the familial transmission of human longevity will be more fully explored.